A002824 Number of precomplete Post functions. (Formerly M3053 N1237)

1, 3, 18, 190, 3285, 88851, 3640644, 220674924, 19427552055, 2448107338105, 436330306419678, 108909970814260122, 37752710546082668409, 18044326480066641231855, 11818118910855384843861960, 10549135258779933616014791704, 12772521057179994145518171256587

Offset

2,2

References

N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

E. Ju. Zaharova, V. B. Kudrjavcev, and S. V. Jablonskii, Precomplete classes in k-valued logics. (Russian) Dokl. Akad. Nauk SSSR 186 (1969), 509-512. English translation in Soviet Math. Doklady 10 (No. 3, 1969), 618-622.

Links

Table of n, a(n) for n=2..18.

Ivo Rosenberg, The number of maximal closed classes in the set of functions over a finite domain, J. Combinatorial Theory Ser. A 14 (1973), 1-7.

Ivo Rosenberg and N. J. A. Sloane, Correspondence, 1971

E. Ju. Zaharova, V. B. Kudrjavcev, and S. V. Jablonskii, Precomplete classes in k-valued logics. (Russian), Dokl. Akad. Nauk SSSR 186 (1969), 509-512. English translation in Soviet Math. Doklady 10 (No. 3, 1969), 618-622. [Annotated scanned copy]

Formula

a(n) = binomial(n, 2) * A001035(n - 2). - Sean A. Irvine, Aug 24 2014

Mathematica

A001035 = DeleteCases[Import["https://oeis.org/A001035/b001035.txt", "Table"], b_ /; ! MatchQ[b, {_Integer, _Integer}] ][[All, 2]];
a[n_] := Binomial[n, 2] * A001035[[n - 1]];
Table[a[n], {n, 2, Length[A001035] + 1}] (* Jean-François Alcover, May 11 2019 *)

Crossrefs

Cf. A001035.

Sequence in context: A178014 A258659 A363414 * A259336 A308134 A160707

Adjacent sequences: A002821 A002822 A002823 * A002825 A002826 A002827

Keyword

nonn

Author

N. J. A. Sloane

Extensions

More terms from Alois P. Heinz, Jun 02 2017

Status

approved